Improvement in joint-clamps



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Letters Patent No. 79,116, dated June 23, 1868.

IMPROVEMENT IN JOINT-GLAMPS.

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f lO ALL WHOM IT MAY CONCERN Be' it known that I, DAVID E. HALL, ofDetroit, in the county of Wayne, and State of Michigan, have inventedcertain new and-useful Improvements in Joint-Clamps; and I do herebydeclare that the following is a full and complete description of thesame, reference being had to the accompanying drawings, milking part ofthis specification, in whichl l Figure 1 is a side-view of the clamp.

Figure 2, a. view of the edge.

Figure 3, a. perspective view of a corner of a box, with the clamp inplace.

Like letters of reference refer to like partsin the different views.

This clamp consists of a. thin plate ofsteel or other metal, fig. 1,bent at a right angle through its diameter, as shown in fig. 2. On eachwing of the clamp, and on both sides of the same, are struck up barbs,A, the points of which, as will be seen,- are in the direction oftheangle, the purpose of which will hereafter be shotwn.

The practical use of this clamp is for staying the corner-joints ofboxes, picture-frames, &c.,. thereby dispensing with the use of nails,or the insertion of ties, as is usually done for this purpose, the clampbeing much stronger, and whollyunseen when applied, which is done asfollows, viz:

In fig. 3, B represents the sides of a. box,'the joint of which is amitre. In the edge of the Ijoint is'sawn a groove, of the thickness of.that of the clamp. Into these grooves are inserted the wings of theclamp, and

' which are forced in on bringing the joint together, thereby bringingthe clamp in the wood, as indicated by the dotted lines C, iig. 3, thesharp-pointed barbs preventing the clamp from pulling out, so that thejoint is held `strongly together, requiring no nails, glue, or any otherfastening for ordinary Work.

I do not confine myself to any particular shape of the clamp. A narrowplate, bent to the proper ongle,

' and provided with barbs, may be used with good results, insecuring'the'joint, by inserting it in the same manner.

What I claim as my improvement, and desire to secure by Letters Patent,isl The herein-described metallic clamp, when constructed in the manneras and forthe purpose set f orth.

DAVID E. HALL.

Witnesses:

J. H. Bunninen, E. E. Wurm

